Nu-haloalkenyl dithiocarbanilates for the control of undesirable vegetation



United States The present invention relates to a new class ofdithiocarbarnates and to methods for making them. More particularly theinvention relates to esters of N-haloalkenyldithiocarbamic acids.

Dithiocarbamates, as are known, all contain the char acteristic andcommon grouping -Nii-s- The compounds of the present invention arecharacterized by the presence of one cyclic group as well as a halogensubstituted alkenyl group attached to the nitrogen of thischaracteristic group. The new compounds comprised in the presentinvention may be represented schematically by the following generalformula where A represents an aryl radical and R represents a halogensubstituted alkenyl group and R represents a nonaromatic ester radical.Typical examples of A are phenyl, p-chlorophenyl, o-chlorophenyl,m-bromophenyl, 2,4-dichlorphenyl, 2,4,5-trichlorophenyl,2,6-dichlorophenyl, otolyl, p-tolyl, rn-tolyl, 2,3,6-trichlorophenyl,2,5-dibromophenyl, m-fiuorophenyl and p-iodophenyl.

The radical designated R may be selected from a variety of halogensubstituted alkenyl radicals but is preferably a halogen substitutedlower alkenyl group as for example Z-chloroallyl, 2-bromoallyl,3-chloroallyl, 3- iodoallyl, 2-fluoro-3 choroallyl, 3-bromo-2-butenyl,2,3- dichloroallyl, 3,3-dichloroallyl, 2,3-dichloro-2-butenyl, 2,3-diodo-2-butenyl and 2,3-dichloro-4-bromobutenyl. The ester radicaldesignated as R may be the same as R or may be lower alkyl or loweralkenyl. In general, any non-aromatic ester radical includingparticularly lower allyl and lower alkenyl radicals is suitable.Examples are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, amyl,allyl and cyclohexenyl. The invention will be fully understood andapparent from the detailed examples which follow.

EXAMPLE 1 Into a reactor was charged 61 grams of N-2-chloroallyl3,4-dichloroaniline, 60 ml. of ethyl alcohol, and 30 grams concentratedammonium hydroxide. The solution was stirred at to it added 33 grams ofcarbon bisulfide in one portion. The reaction mixture was held at 2530C. for one hour and 42.6 grams of methyl iodide added in one portion.The reaction mixture was stirred at 2530 C. for 24 hours then 400 ml. ofwater added and the reaction mixture was extracted with 400 ml. of ethylether. The ether solution was washed with dilute hydrochloric acid untilthe aqueous layer did not yield any amine upon neutralization with 25%sodium hydrochloride, then washed with water until neutral to litmus,dried over sodium sulfate and the ether removed in vacuo at maximumtemperature of 8090 C. at 1-2 mm. There was obtained 78.5% yield ofmethyl N-2-chloroallyl 3,4- dichlorodithiocarbanilate, an amber oil.

Substituting 33.3 grams of 2,3-dichloro-l-propene, 23.0 grams of allylchloride and 31.1 grams of 2-bromo-3- chloral-prewar respectively forthe methyl iodide and atent 54.5 grams of N-(3-chloro-2butenyl)anilinefor N(2- chloroallyl) 3,4-dichloroaniline and 33.3 grams of 2,3-dichloro-l-propene for the methyl iodide in the foregoing procedureyielded the following products.

The new compounds disclosed herein possess a high degree of biologicalactivity. For example, the class comprise an effective group ofgrass-specific herbicides. In general the presence of an aryl radical onthe nitrogen of a dithiocarbamate detracts from utility as herbicidesbut the new class are exceptional.

In general the compounds effectively control vegetation by applicationthereto by which is meant either application to the soil whereby thetoxicant is brought into contact with germinating seedlings or tofoliage. The compounds are particularly valuable as pre-emergentherbicides wherein the toxicant is applied to the soil before weeds andother plants emerged. The toxicants may be applied conveniently in theform of a spray containing the active ingredient within the range of0.15%. For pre-emergence application amounts within the range of 1 to 60pounds per acre are recommended. The active components are insoluble inwater but they are soluble in common organic solvents. They may bedispersed directly in water or dissolved first in an organic solvent andthen dispersed. As dispersing and wetting agents there may be employedsoft or hard sodium or potassium soaps, alkylated aromatic sodiumsulfonates such as sodium dodecylbenzenesulfonate, or an amine salt ofdodecylberr zenesulfonic acid, alkali metal salts of sulfated fattyalcohols, ethylene oxide condensation products of alkyl phenols or talloil and other dispersing and wetting agents. The herbicides may beformulated and applied as dry compositions by mixing the toxicant with afinely divided solid carrier, as for example talc, clay, pyrophyllite,silica and fullers earth. Alternatively, the dry composition may bedispersed in water and applied as a spray.

The table below illustrates the pre-emergent herbicidal activity of thenew compounds. In these tests the ester was emulsified in water and theemulsion applied as a spray. The active ingredient at 25 pounds per acrewas applied to the soil of seeded plots before the grass or other plantsemerged. For convenience in recording the data the following rating keywas employed. 0No phytotoxicity. l-Slight phytotoxicity. 2Moderatephytotoxicity. 3Severe phytotoxicity.

The plants are represented by letter as follows:

A. Morning glory H. Cotton B. Wild oat J. Corn C. Brome cheat grass K.Foxtail D. Rye grass L. Barnyard E. Buckwheat M. Crab grass F.Radish-mustard N. Field bindweed G. Sugar-beet 9, P erced Table H ActiveIngredient A B C D E F G H .T K L M N MethylN-(2-chloroallyl)3,4-dichlorodithiocarbanilate 3 3 3 3 2 1 3 1 0 3 3 3 13 2-Ohloroailyl (2 dithiocarbanilate 0 3 3 3 2 1 3 1 3 3 3 3 0 3Z-Brornallyl N-(2-chl0roallyl)-3,4-dichlorodithiocarbanilate 0 3 3 3 0 l3 0 0 3 3 3 0 3 Allyl N-(Q-chloroallyl)-3,4-dichlorodithiocarbanilate..03230030033303 Toxicity to foliage was demonstrated by spraying theWhat is claimed is: foliage of grass, bean and a mixture of broadleafplants 1. A compound of the structure with an aqueous spray containing0.5% of the toxic ingredient. The results employing the same numericalrating system are recorded below.

B Table III where A represents an aryl group selected from the group Aconsisting of phenyl and halogen substituted phenyl, R Phytotoxlcltyrepresents a halogen substituted lower monoolefinic group ActiveIngredient and R is a radical selected from the group consisting ofGrass Bean ig lower alkyl, lower monoolefinic and halogen substitutedlower monoolefinic. MethylN-(2-chloroallyl)3,4-diehl0rodithiocar- ACompound of the Structure banilato 2 3 3 2-Ohl0roallyl N 2-chloroally1)3, 4-dichlorodi- S thiocarbanilate 2 2 2 ii 2-BromoallylN-(2-chloroallyl)-3,4-dichlorodi- A-NCSR thiocarbauilate 1 3 3 i AllylN-(2-chloroallyl)-3,4-dichlorodithiocar- R banilato 2 a 2 where Arepresents chloro substituted phenyl, R repre- I sents a hologensubstituted lower mono-olefinic radical As illustrative of the toxicityto nematodes an experland represents a lower alkyl radical ment wasconducted by preparmg a suspension of the A mmpmmd of the structurenematode Panagrellus redivivus in water and observing through amicroscope the motility of the organism in the presence ofN-Z-chloroallyl 3,4-dichlorodithiocarbanin late. A control experimentwas run at the same time in which no toxicant was employed. The nematodein a(P160118 susphhsioh W111 flex its y at a regular rate and where Arepresents a halogen substituted p'ncnyl group, as the nematocide takeseffect, the Tale Of flexing R represents a halogen substituted lowermono-olefinic creases until death of the Parasite OCCUIS- The Controlradical and R represents a lower monoolefinic radical. experiment showedundiminished activity after 24 hours 4, A compound f h Structura whereasthe motility was only 5% of the original in the presence of 0.1% of thetoxicant. i

The new compounds comprise compounds toxic to ANC-SR fungi which retaintheir toxicity in the presence of soil. They are therefore valuable fordestroying other pathogenic organisms besides nematodes present in soil.At a where A represents a dichlorophenyl radical, R repreconcentrationof 100 p.p.m. Z-bromoallyl N-Z chlorosents a 2-chloroallyl radical and Rrepresents a halogen allyl 3,4-dichlorcdithiocarbanilate and allylN-Z-chlorosubstituted lower monooiefinic radical. allyl3,4-dichlorodithiocarbanilate were toxic to damping 5. 2 chloroallylN-(3-chloro-2-butenyl)-phenyldithiooff organisms present in soil. Inmicrobiological testing carbamate. these compounds and methylZ-chloroallyl 3,4 dichloro- 6. Methyl N-(Z-chioroallyl)3,4-dichlorodithiocarbanidithiocarbanilatc prevented the growth ofMicrococcus late. pyogenes var. aareus and Aspergillus niger atconcentra- 7. 2-chloroallyl N-(Z-chloroallyl) 3,4-diohlcrodithiotions of10 ppm. The toxicity to microorganisms was carbanilate. retained in thepresence of soap rendering the compounds 8. 2 bromoallylN-(Z-chloroallyl)-3,4-dichlorodithiouseful as antiseptics in alkalimetal higher fatty acid salt carbanilate. detergent soaps. Still furtherbiological activity was 9. Allyl N-(2-chloroallyl)-3,4-dichlorodithiocarbanidemonstrated in tests against insect pests.100% kill of late. yellow mosquito larvae was achieved with 000170 con-1 A herbicidal composition comprising a major procentrations of2-chloroallyl N(3-chloro-2-butenyl) dithio- Portion of a cauier and aminor phytotoxic Proportion of carbanilatc, methyl N-(2-chloroallyl')3,4-dichlorodithiothe compound of the Structure carbani-late,2-chl0roallyl N(2-chloroallyl) 3,4-diclr oro- 55 di thiocarbanilate,Z-bromoallyl N-(Z-choroallyl) 3,4-dili chlorodithiocarbanilate and allylN-(2-ohloroallyl) 3,4-dii chlorodithiocarbanilate. R

It is Intended to an Fhanges and modifications where A represents anaryl group selected from the group of the examples of the inventionherein chosen for purconsisting of phenyl and halogen Substituted pheny!R P of disclosure which do not commute departures represents a halogensubstituted lower monoolefinic group from ihe Spirit and Schpe 0fihvehtiohand R is a radical selected from the group consisting Thisapplication is a cohiil'lllaiiondn-Pmt Of 011T of lower alkyl, lowermonoolefinic and halogen substipending application Serial No' 474,984,filed December tuted lower monoolefinic.

13, 1954, now US. 2,854,467, granted AprilSO, 1958.

11. A herbicidal composition comprising a major proportion of a carrierand a minor phytotoxic proportion of the compound of the structure s.AN(%SR' I l where A represents chloro substituted phenyl, R representsa halogen substituted lower mone-olefinic radical and R represents alower alkyl radical.

12. A herbicidal composition comprising a major proportion of a carrierand a minor phytotoxic propontion of the compound of the structure whereA represents a halogen substituted phenyl group, R represents a halogensubstituted lower monoolefinic radical and R represents a lowermonoolefinic radical.

13. A herbicidal composition comprising a major proportion of a carrierand a minor phytotoxic proportion of the compound of the structureAN(JSR it Where A represents a dichlorophenyl radical, R represents a2-chloroallyl radical and R represents a halogen substituted lowermonoolefinic radical.

14. A method of controlling vegetation which comprises applying theretoa phytotoxic concentration of a compound of the structure 6 v where Arepresents chloro substituted phenyl, R represents a halogen substitutedlower mono-olefinic radical and R represents a lower alkyl radical.

16. A method of controlling vegetation which comprises applying theretoa phytotoxic concentration of a compound of the structure i A-N-OSR'where A represents a halogen substituted phenyl group, R represents ahalogen substituted lower mono-olefinic radical and R represents a lowermonoolefinic radical.

17. A method of controlling vegetation which comprises applying theretoa phytotoxic concentration of a compound of the structure where Arepresents a dichlorophenyl radical, R represents a 2-chloroa1lylradical and R represents a halogen substituted lower monoolefinicradical.

References Cited in the file of this patent UNITED STATES PATENTS Re.22,750 Tisdale et al Apr. 30, 1946 2,127,375 Bousquet Aug. 16, 19382,535,877 Stewart Dec. 26, 1950 2,744,898 Harman et al. May 8, 19562,766,554 Dorman Oct. 16, 1956 2,854,467 Harman et a1 Sept. 30, 19582,863,899 Harris Dec. 9, 1958 2,893,856 Hamm July 7, 1959 2,919,182Harmon et al. Dec. 29, 1959 FOREIGN PATENTS 205,460 Australia Jan. 16,1957 858,352 Germany Dec. 4, 1952 OTHER REFERENCES Metcalf: Advances inPest Control Research, publ. by Interscience Publ., 1957, pages 67 and68.

Plant Regulators, page 27, Chemical-Biological Coordination CenterPositive Data Series, No. 2, June 1955.

1. A COMPOUND OF THE STRUCTURE
 14. A METHOD OF CONTROLLING VEGETATIONWHICH COMPRISES APPLYING THERETO A PHYTOTOXIC CONCENTRATION OF ACOMPOUND OF THE STRUCTURE